Transmission-gear system



w. F. PENROD. TRANSMISSION GEAR SYSTEM.

APPLICATION FILED APR. 15, 1 921.

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W. F. PENROD.

TRANSMISSION GEAR SYSTEWL' APPLICATION FILED APR. 15 1921.

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'WISSEL, TRUSTEE.

TRANSll/L'ISSIQN- Application filed April 15,

To (all whom it may concern:

Be it known that 1, "WILLIAM Fnaniuim PENROD, a citizen of the UnitedStates, residing at Cincinnathin the county oil Hamilton and State ofUhio, have invented new and useil ul. Ilmproveniei'its in Transmission-Gear Eiystems or which the following is a specification.

My invention relates to power-transrnitting gear systems such as areused in automotive vehicles; its object being the llll prwement of thestructure and operative relations ip oi? the elements composing thesame, tending, primarily, to simplicity 0t structure, reduction ofinitial cost and a more economical use of power, on the one hand, andincreased e'lliciencg. and. durability on the other.

The i1n1n'oveim-n1t also contennplates an increased range ofapplicability by the system and arrangement of change gears andoperative elements whereby the improved system is adapted to use bothwith autoinotive trucirs and also to passenger car service; and in bothwith smooth and practically noiseless operation.

To these and cognate ends, the invention consists 1. In a driving andtransmitting system embodying the application ct power to an ultimatelydriven shaft or axle. through parallel shafts arranged atright angles tosaid ultimate sha'lt by gears provided with helical teeth so imrlinedand relatelil as to produce opposing and neutralizing end. thrustsabsorbed by the gears involved. in all speed changes; thereby renderingspecial thrust bczuings umnuressary by a relation practically realizinga herring bone tooth system of gear operation and elinfiinating allextra strains on the case or case bearings.

In a structure and relation of parts wherein more direct speeds arerealized with fewer transmission elements than are attained in standardpractice.

3. in a; structure and arrangement of parts whereby the driving power isdelivered by two thrust balanced bevel pinions simultaneously, atopposite sides to a-ring gear with self-adjusting equalization of loadcurried thereby.

specification of Letters Patent.

GEAR SYSTElvI.

Patented Aug. 11, 19252.

1921. Serial No. 461,564.

urther details will appear in the specification following.

In the drawings forming part of this sieeiiication, Figure l is a planview of a system of change gearing embodying my invention, sectionedthrough the common plane of both the driving and driven shafts; andFigures 2 to 6 inclusive, are plan views, in the nature oi? diagrams,showing the direction of power transmission in the several speed changesandgear connections; indicating by the arrows the direction oi the endthrusts created illustrating the principle of balancing by opposingthrusts conlined to the gears involved as a matter of tooth pressures;Fig. 2 is low gear. Fig. 3 is over geared. that is for drive of bevelpinions at greater than engine speeed. Fig. t is direct or engine speeddrive. Fig. is intermediate drive. Fig. 6 is the reverse.

Refer ingnow to the accompanying drawings, A desi nates a supportingframe for the mechanism herein described, provided with suitablebearings for a main or initial power shaft an axially abutting and indeiiendently rotatable extension thereof designated as the tension shaftand an auirili. sh a tt S in parallel relationswith mentioned. I

on shaft S and the auxiliary shaft 55 y equal terminal bevel pinioiis 7)F, in constant driving relations with a d(, ul: le-tootlied ring gear Rfixedly attached to the difiierential casing of the driven- .iizlc (notshown). Immediately torward oi" the pinions. p p are located supportingbearings 72. 71 for the extension and auxiliary shafts, and adjacent tothese bearings are a pair of equal constant mesh spur gears gi-one uponeach of saidjsha'fts. The combined. structure oi bevel-pinions. shaftsand intermeshing spur gears of each shaft reg rded as a whole and ascarried by the intervening bearings b in common. constitute a unit ofstructure and may be integral asto each shaft respectively. The systemcontemplates an equal division of powerbetween the driving pinions and.their imme diate shafts at all times by which the normal stress upon.and wear of parts is minimized by distribution between the two pinions.

The contiguous end-portions of the main and extension shafts are ofsomewhat reduced diameter and are carried in abutting relations in pilotbearings 83* 5 within an axial perforation through a spur gear 9 and itslaterally extended hubs which are themselves carried in case bearings 66, upon the frame A. The perforation of gear 9 covers a zone of freerotative contact at both sides of the plane of severance between theabutting shafts S p in such wise that each shaft may be rotatedindepi-mdently of the other, or they may be connected into one. Theenclosing perforation of the gear is slightly enlarged immediatelyadjacent to the plane of severance of the abutting shafts S b for thereception of contact washers between their contiguous surfaces. Splinedclutches C C adjacent to the hub-ends of the gear 9 at opposite sidesrespectively, serve to connect said gear in rotation with the main shaftS or the extension shaft :3 or both as required. The gear 9 is inconstant-mesh with an opposite loose gear g, on sleeve S of theauxiliary sh alt as will be explained later. Forward of the gear 37 is agear 9 permanently aflixed to shaft S in constant mesh with a normallyloose gear 9 upon the sleeve S of the auxiliary shaft. Adjacent totheseare the forwardprincipal 7 bearings b 6 upon the frame A. The mainbearings Z2 b of theshafts are preferably of the straightroller type.Forwardly adjacent to the bearings 6 6 is a permanent gear 9 upon themain shaft, used only in reversing.

The auxiliary shaft S is integral from its rear bearing 5 forward to acase bearing 0.

From its rear permanent gear forward it carries a loose sleeve Senclosing a pilot bearing (5 adjacent to said permanent gear 9 andterminating forward in a spur gear 9 in constant mesh with a similargear g upon the main shaft S (these two last mentioned gears being usedonly in reverse motion). Adjacent to the permanent gear the sleeve isprovided with a splined shifting clutch c to engage the sleeve inrotation with the shaft S. Forward of this is'a permanent gear 9 inconstant mesh with the gear 9 of the main shaft S and still forward is aloose gear 9 in constant mesh with gear gr of the main shaft S andprovided with a sliding clutch C to engage it in rotation with thesleeve S and next forward are the case bearings 6 In connection withthese bearings the forward end of the auxiliary shaftirl is somewhatreduced in diameter to receive a case thrust bearing 6.

The employment of two oppositely rotatingbevel' pinions p simultaneouslyto drive the ring gear, with initial application of power to one or theother pinion as the case may be, results, practically, in .a tendency tounequal distribution of load between the pinions which may becounteracted by provision of differential mechanism or by the simplermethodof giving to the extension shaft S a slight end play to allow aself-adjustment or change of the tooth contact pressure as between thebevel pinion p and gear and ultimately with the other bevel pinion 22 Tothis end I mount the main and extension shafts S S with slight end playand secure to the abutting end of each shaft a disc al of hardened steelwith bronze washers d (P, and interpose between the discs (Z a pluralityof independent hardened rollers d said discs, washers and rollerstogether constituting a thrust bearing which takes the pressure ofcontact when ever thrust action takes place. The slight end clearanceallows the tooth-pressures between the opposite driving pinions p p toequalize themselves by the slight yielding of the driving pinion to thepoint of equal pressure on the teeth of both pinions. This end movementmay be allowed on one or both of the shaft sections S S This holds goodin all movements of the vehicle whether the power is delivered primarilythrough the bevel pinion p or 72 Thenormal end thrusts of the gear-coirnections are minimized and practically eliminated by the use andarrangement of helically cut gears in such relation and tooth. angles asto secure what may be termed herring bone effect, having in mind theprinciple that the direction of thrust in a driving gear opposite tothat of a driven gear running in the same direction both gears havingthe same hand helix rotative direction. This is illustrated in Figures 2to Ginclusive. It will be observed that the spur gears g g 9 of the mainand extension shafts h ave teeth of similar inclination opposite to thatof the teeth of bevel pinion 79 While the teeth of the correspondinggears 9 g, and also g of the auxiliary shaft are inclined oppositely tothose first 1uentioned and in the same direction as the teeth of pinion79 In the figures of the drawing referred to, the transmission of powerindicated by direct and cross lines showing its course from shaft toshaft and gear to gear, with small arrows indicating at each gear thedirection of thrust in each case. Thus in Figure 2 representing lowgear, the course of power transmission from main shaft S is to gear 9thence across to gear 9; rearward to 9 across to gear 9 and rearwarddirect to pinion p with a side branch from gear 9 to gear 9 and thencedirect to pinion p In this transmission as shown by the arrows, (seeFig. 2) gear thrusts rearward, being a driving gear, while gear g" beingdriven, thrusts forward; gear g being a driving gear as to its companiongear 9 thrusts backward. Thus as between these esa-n10 oppositeintermeshing gears those on the auxiliary shaft counteract by thrustaction in direction apart from each other while the main shaft gearscounteract thrust action toward each other. Similar counteracting effectwill be evident as between companion gears g y and the bevel pinions p,71 each set of opposite counteracting each the thrust action of thecorresponding gear of the next in series.

In case of a reversal of torque as in running down hill and braking withthe engine, all thrusts are reversed in direction, but substantiallybalance.

In the transmission as shown by the arrows (see Fig. 5 gear 9 thrustsrearward, being a driving gear, while gear 9 being driven, thrustsforward, gear g being a driving gear, thrusts backwards, and itscompanion gear 9 being a driven gear, thrusts forward. Pinion and gear 9both thrust forward and are balanced by the backward thrust of g. Pinionand both thrust backward and are balanced by the forward thrust of g". i

The principle involved, o'l counteracting thrust action. is illustratedin similar Figures 3, a and 6 which. differ only in the relative changesin the course of transmission involved in change of speed, and will beevident without further detail of ca;- planation.

It will be seen that the thrust actions throughout are thus confined toand neutralized by the relation of the moving elements to each other intheir several contacts to the exclusion of all case-bearings for hispurpose. The main thrust at the point of delivery of power through thedriving pinions to the ring gear is absorbed by the self-adjustingequalization of load pressure upon the pinions permitted by the slightendwise movement of the primary engaging pinion and the shaft of which.said pinion is the terminal. The inter-meshing transmission gears on theparallel shafts have helically cut gear teeth rights and leftsrespectively. In the construction and arrangement of the parts, thebalancing normal of thrust action as between the several helically cutspur gears, is such that the thrust action of one pair of gears isbalanced at one speed by a given set of gears and at a different speedby the other pair of gears brought into use.

It will be observed also that each pair of intermeshing gears isemployed in more than one speed, thus minimizing the number of gearsused in. the system.

f'lcvcral important advantages are realized among which are thefollowing: The relatively increased strength of parts as gained by thedivision of power through two ultimate driving pinions, is of courseobvious and has already been suggested; but to coinbine this structuralfeature with the various other elements of a transmission system involving different speeds without interfering with continuity of rotationof the pinions, presents a problem whose solution has not heretoforebeen accomplished,

In the present invention the speeds are more direct and employ a lessnumber of gears in the same number of speed changes than is now thestandard practice. More over the invention renders possible a practicalovergeared speed,-that is, one in which the pitchline velocities are nottoo high for efficient service. Also, it connects two shafts in rotationby helical cut gears, so that the relation of driving to driven gearsmay be reversed without imposition of extra strain upon the case or anyof its bearings.

In addition to these is the realization in a standard motor-drivenvehicle of the elimination of noise and clatter usually to be expectedin a pluralization of speeds, and the substitution of ellicient smoothand quiet running, enabling the vehicle to be used continuously atdirect or high speed, due in part to the principle of opposing thrust byan opposite thrust; which carries with it the practical effect ofherring bone balanced structure.

There is thus constituted a gear-system in which the power is divided inits ultimate application to tne axle, through two parallel shafts, inequal moieties to and through two equal bevel pinions in mesh with thering gear at opposite sidessimultaneously. This of course reduces byone-half the stress upon the engaging teeth of the ring gear the bevelpinions p p and the spur gears 9 g with reduction of frictional wear.

It also provides for a gear ratio much.

' indicated, emliiodiying a differential axle casing; a double bevelring gear seated thereon; a main shaft and an independently rotatableextension thereo'i'ia countersha'lt in parallel with said main andextension shafts; equal bevel pinions on the rear extremities of saidextension and countershafts in constant driving relations with the ringgear; a spur gear having a hollow body and hub-extensions the lattercarried in bearings support ing the gear body and the abutting shaftterminals embraced therein; and pilot bearwithin the enclosure of thegear body for each abutting shaft terminal.

2. In a gear transmission system all gears of which are helicallycut;the combination of a double bevel ring ear; initial drive shaft made intwo parts; a combined thrust bearing and clutch forming a connection forCir selves the end thrusts of said double pinions at all speeds.

3. In a gear transmission system all gears of which are helically out;the combination of a double bevel ring gear; an initial drive I shaftmade in two parts tandem; a combined thrust bearing and clutch forming aconnection for the parts ofsaid shaft permitting slight lost motionendwise; a secondary drive shaft; said drive shafts parallel and atright angles to the axis of said ring gear; a terminal bevel pinion foreach drive shaft engaging said ring gear at opposite sides insimultaneous driving relations; a plurality of gears for said shafts fordriving said ring gear at varying rates of speed, so arranged as topermit and require the delivery of 7 power through both said terminalpinions upon the ring gear ineach of said speeds; and to balance asbetween themselves the end thrustsof said double pinions at all speeds,

and automatically equalize the tooth pressure and maintain equality ofload between the two terminal pinions.

4. In a gear transmission system of the general character described allgears of which are helically out; the combination of a differentialaxle-casing double bevel ring gear seated there0n;'an initial driveshaft made in two parts; a combined thrust bearing and clutch forming ;aconnection for the parts of said shaft; a secondary drive shaft; anormally loose sleeve for said secondary shaft; said drive shaftsparallel and at right angles to the axis of said ring gear; a terminalbevel pinionfor each driveshaft engaging said ring gear at oppositesides in simultaneous driving relations; a plurality of gears for saidshafts and sleeve for driving said ring gear at varying rates of speed,so placed and mounted as to permit and require the delivery of powerthrough both said terminal pinions upon the ring gearin each of saidspeeds; and to balance as between themselves the end thrusts of saiddouble pinions at all speeds, and sufficient end play in said initialdrive shaft to automatically equalize the tooth pressure and maintainequality of load between the two terminal pinions.

5. In a gear transmission system'of the character indicated, having adivided mainshaft, and a gear body formed to embrace 6. In a geartransmission ofthe character indicated, in combination with a maindriving-shaft in two parts independently rotatable in tandem relations,and carried at the zoneof their abutting contact within the axialorifice of a spur-gear carried in case bearings; a bearing washer orwashers secured at the contiguous shaft-ends and constituting a thrustbearing. 1

7. In a power transmission system of the character indicated, a mainpower shaft, a tandem extension thereof; a spur gear 'struc-V ture withhollow center constituting a, rotative support; thrust bearings atithecontiguous ends of the. main and extension shafts, the construction ofthe said spur gear in two duplicate parts substantially as shown tofacilitate and cheapen the structure and afford readyaccess to theintel'lOl thereof for renewal of minor parts. 8. In a transmisslon gearsystem the combin-ation of a plurality of shafts; two driv- I 111gpinions one upon each of two shafts; a double ultimately driven bevelgear in constant mesh with said driving pinions simultaneously; and aplurahty of change gears on said shafts for securing varying rates ofspeed, said gears being so placed and mounted as to permit and requirethe double drive of the pinions upon the ultimate driven gear in'each ofsaid speeds, all of gears being helical. 9. In a transmissiongearsystem, the combination of a plurality of shafts, two drivingpinionsone upon each of two shafts, a double ultimately driven bevel gear inconstant mesh with said driving pinions simultan'eously; and a pluralityof change gears 111 such location and inter-relationas that power may bedelivered initially through one or the other of said ultimate drivingpinions, while preservingcontinuity of rotation of both, all of saidgears being helical.

10. In a transmitting system of the character indicated,a main shaft; anaxially abutting independently rotatable extension thereof; acounter-shaft in parallel with said main and extension shafts a maincentral spur-gear axially embracing and constituting a bearing for theabutting terminals of said main and extension shafts; and a plurality oftransmitting gears located as opposites in location in fast or looseconnection upon opposite shafts, vand made available in the variablespeed relation by clutches severally connecting them for drivingrotation with the shaft upon which the gear is located.

10 tible therewith in rotation as desired; a

spur gear normally loose upon said sleeve in mesh With a correspondingpermanent gear upon the main shaft.

In testimony whereof I have hereunto set my hand in presence of tWosubscribing witl5 ,nesses.

WILLIAM FRANKLIN PENROD. Witnesses:

CARL PHARES, NORMA D. BERGER.

